Method of manufacturing semiconductor device

Abstract

A semiconductor device includes a semiconductor layer formed on a substrate, an electrode contact window that includes a recess formed on a surface of the semiconductor layer, an inner wall having a slope, and a source electrode, a drain electrode, and a gate electrode formed on the semiconductor layer, in which the drain electrode is in contact with the slope of the inner wall.

What is claimed is: 
     
       1. A method of manufacturing a semiconductor device, the method comprising:
 forming a semiconductor layer on a substrate; 
 forming a first resist on the semiconductor layer; 
 forming a second resist on the first resist; 
 forming a first opening pattern of the first resist and a second opening pattern of the second resist, the first opening pattern and the second opening pattern being overlapped with each other; 
 performing isotropic etching on the semiconductor layer through the first opening pattern and the second opening pattern so as to form a recess on a surface of the semiconductor layer, the recess having a slanted slope; and 
 forming an electrode on the recess of the semiconductor layer which is exposed from the first opening pattern and the second opening pattern. 
 
     
     
       2. The method according to  claim 1 ,
 wherein the semiconductor layer is formed by an electron transit layer on the substrate, an electron supply layer on the electron transit layer, and a cap layer on the electron supply layer, and 
 wherein a bottom of the recess is formed at a surface of the electron supply layer. 
 
     
     
       3. The method according to  claim 2 ,
 wherein the electron transit layer includes GaN, the electron supply layer includes AlGaN or InAlN, and the cap layer includes GaN. 
 
     
     
       4. The method according to  claim 2 ,
 wherein the electrode is formed so as to be in contact with the bottom and the slanted slope of the recess in the forming of the electrode. 
 
     
     
       5. The method according to  claim 1 ,
 wherein the electrode is a source electrode or a drain electrode. 
 
     
     
       6. The method according to  claim 1 ,
 wherein a size of the first opening is greater than that of the second opening. 
 
     
     
       7. The method according to  claim 1 ,
 wherein the performing of the isotropic etching is conducted after performing anisotropic etching on the semiconductor layer through the first opening pattern and the second opening pattern. 
 
     
     
       8. The method according to  claim 7 ,
 wherein any of Cl 2 , BCl 3 , and SiCl 4  is used for the isotropic etching and the anisotropic etching. 
 
     
     
       9. The method according to  claim 7 ,
 wherein the isotropic etching is wet etching, and 
 wherein potassium hydroxide or sodium hydroxide is used for the wet etching.